The present invention generally relates to pressure regulation systems, and more particularly to hybrid electronic-mechanical systems that incorporate electronic controls with mechanical regulator capabilities.
Traditional mechanical regulators balance outlet pressure forces against the flow forces on a proportional flow area. As inlet pressure and temperature change, these forces change, but the regulation force (applied by a pressurized dome or spring) remains constant. This results in movement of the system's equilibrium point, and a corresponding change in outlet pressure, which is often called “droop.” This error can be a significant portion of the set pressure across the operating range of the regulator. Pressure regulators that are purely mechanical have inherent drawbacks, primarily deviation from set point, or droop, during operation. Secondary sources of error are unit-to-unit variability and accumulated wear throughout operational life resulting in variations of output pressure.
There remains room for improvement in the design and use of pressure regulators, particularly with regard to the ability of such systems to operate efficiently and reliably at high inlet pressures.